That might mean that they are boys.
um, yes.... just looked it up. The drakes have some curl on the tail, females don't. I guess those Northern ducks are headed to freezer camp for sure now! On the plus side, I read that the males have a softer quack than the female Pekins...
Yep... for example the drake in the picture above has that curly tail (drake feather). Boys rasp, not a true quack so it is easy to tell from the sound once they're 6-8 weeks+